The Blood Coagulability in Diabetic Patients

Thirty diabetic patients and 30 normal persons were investigated as to the blood clotting systems.

The results revealed a relative hypercoagulability in the diabetics, as evidenced by a shorter average plasma cephalin time and high average values for plasma AHA (f. VIII), proaccelerin (f. V) and fibrinogen. The average increase, as compared with the normals, was for AHA 70 per cent, for proaccelerin 23 per cent and for fibrinogen 44 per cent.

The observed changes in the clotting systems may have relation to the high incidence of thrombosing atherosclerosis associated with diabetes mellitus.     

A Stochastic Control Program to Predict Outcome and to Support Therapeutic Decisions: A Preliminery Report

Background and Objectives. Early noninvasive hemodynamic monitoring with an outcome predictor and a therapeutic decision support system may be useful to identify and correct hemodynamic deficiencies in emergency patients. The first aim was to apply a stochastic (probability) search and display model to predict outcome as early as possible. The second aim was to explore the usefulness of a therapeutic decision support system to evaluate the relative effectiveness of various therapies. Methods. A stochastic control and display program based on noninvasive hemodynamic monitoring was applied in 100 consecutive critically ill patients admitted to the emergency department of an inner city public hospital. The program continuously displayed the noninvasive hemodynamic data and the patient's predicted survival probability (SP) that was based on the patient's diagnosis, covariates, and hemodynamic data. The accuracy of the SP at the initial resuscitation on admission to the emergency department (ED) was evaluated by the actual outcome at hospital discharge. The therapeutic decision support program evaluated the relative effectiveness of various therapies on based on their hemodynamic and SP responses and outcome of patients with similar clinical-hemodynamic states. Results. The cardiac index, mean arterial pressure, arterial saturation, transcutaneous oxygen and carbon dioxide tensions were appreciably higher in survivors than in nonsurvivors in the initial resuscitation. Heart rate was higher in the nonsurvivors. The calculated Survival Probability (SP) of survivors averaged 81 ± 1.4% in the first 24-hour observation period. It was 58 ± 2.2% for nonsurvivors during this period. Misclassifications were 10/100 or 10%. The content of the information does not necessarily reflect the position or policy of the Government, and no official endorsement should be inferred.     

Evaluation of Capnography in Nonintubated Emergency Department Patients with Respiratory Distress

Objective: To evaluate the ability of noninvasive capnographic measurement of end-tidal CO₂ tension (Petco₂) to predict artenal CO₂ tension (Paco₂) in nonintubated ED patients with respiratory distress Methods: A prospective, nonblind study was performed in a level I trauma centerkommunity teaching hospital ED. Participants included all nonintubated adult patients with respiratory distress requiring measurement of arterial blood gases (ABGs): 29 patients were enrolled Petco_z was measured with a capnography monitor. using both baseline tidal volumes and forced expiratory volumes. The bias between Petco_? values and simultaneous measurements of Paco₂ by ABG was assessed Results: Petco, measured with forced expiration, and Pace_? agreed well, with bias (i.e, average difference) = 044 ± 0.52 kPa (33 ± 3.9 torr). Petco₂ measured with the tidal volume breath produced an unacceptably high bias of 0.82 ± 0.70 kPa (6.1 ± 5.2 torr). Levels of agreement between Paco₂ and Petco₂ were similar for smokers and nonsmokers and for men and women. The arterial-end-tidal CO₂ tension (Pa-etco₂) difference was not related to Paco₂ Pa-etco₂ correlated with age (r = 0.473; p = 0.01), and was significantly higher in patients with pulmonary disease (132 ± 0S6 kPa; 99 ± 42 torr) than it was in those without pulmonary disease (0.46 ± 055 kPa, 3.5 ± 4.1 torr, p < 0.001). Conclusions: Noninvasive Petco_z monitoring may adequately predict Paco₂ in nonintubated ED patients with respiratory distress who, are able to produce a forced expiration. Petco₂ is less accurate for Paco₂ with tidal volume breathing and in patients with pulmonary disease     

Reflectance pulse oximetry at the forehead of newborns: The influence of varying pressure on the probe

Objective: Transmission pulse oximetry (TPO) is not a practical method of intrapartum fetal monitoring of arterial oxygen saturation. Reflectance pulse oximetry (RPO) requires a sensor applied to the skin of the fetal head and may be a useful technique. During labor, various degrees of pressure will be exerted on the RPO sensor. Previous studies have shown that moderate pressure on the sensor can improve the RPO signal. At increasing pressure, however, blood flow underneath the sensor will be occluded. This study examines the influence of pressure applied to the RPO sensor on the signal from the forehead of healthy newborns as a model for the fetal situation.Methods: After institutional approval, 12 healthy newborns were studied. The RPO probe was placed at the forehead. Pressure on the probe was increased stepwise from 0 to 80 mmHg, and the effect on the ratio between the relative changes of the red and infrared light intensities (R/IR, inversely related to oxygen saturation) and pulse sizes was evaluated. Additionally, the effect of firm pressure (>150 mmHg) on the probe was evaluated.Results: R/IR values remained virtually unchanged when pressure onto the probe was increased from 0 to 80 mmHg, although the standard deviation slightly decreased. The pulse size increased as pressure on the probe increased. During firm pressure on the probe (> 150 mmHg), plethysmographic signals remained detectable, but R/IR values markedly increased.Conclusions: In newborns, mild to moderate pressure on the probe has little influence on the RPO signal at the forehead. Even during firm pressure, RPO can be used to obtain pulsatile signals, that presumably derive from tissue underneath the skull, such as the cerebral circulation.     

Hypotension is Uncommon in Patients Presenting to the Emergency Department with Non-traumatic Cardiac Tamponade

Background

Cardiac tamponade is a life-threatening disease in which hypotension is believed to be a common finding. Prior inpatient studies have described normotensive or hypertensive cases of tamponade; however, because the data were not collected from the Emergency Department (ED), the hemodynamic spectrum may differ from those presenting to the ED.

Objectives

We hypothesized that hypotension is uncommon in patients presenting to the ED with non-traumatic tamponade.

Methods

A retrospective chart review was conducted between January 2002 and December 2007 of patients presenting to our ED who were subsequently diagnosed with cardiac tamponade.

Results

A total of 34 patients were identified with a diagnosis of tamponade. The mean blood pressure on ED arrival was 131/79 mm Hg. Upon initial presentation to the ED, 35% (n = 12) of patients were hypertensive, 50% (n = 17) were normotensive, and 15% (n = 5) were hypotensive. Of the 5 patients who were hypotensive on ED arrival, only 2 (6% of all patients) remained hypotensive upon admission to the hospital and before a pericardiocentesis. An average of 995 mL of fluid was removed from the pericardium. The chief complaint for the majority of patients in tamponade was shortness of breath (70%); 59% were tachycardic in the ED, and 72% had cardiomegaly on chest X-ray study.

Conclusions

Hypotension is uncommon in patients presenting to the ED with non-traumatic cardiac tamponade. The majority of patients are normotensive or even hypertensive. Thus, the emergency physician should not exclude the diagnosis of tamponade even in light of normotension or hypertension.     

Noninvasive Doppler blood pressure monitoring in the monoplace hyperbaric chamber

We describe a noninvasive method of monitoring blood pressure in the monoplace hyperbaric chamber. A standard blood pressure cuff was placed on the patient's arm. A Doppler probe, linked to an ultrasonic Doppler flow detector outside the chamber, was secured over the patient's radial artery. Cuff inflation tubing and the Doppler probe wires were passed into the chamber by modifying a standard disposable hyperbaric intravenous pass-through. Blood pressure readings were determined by inflating and slowly deflating the cuff from outside the chamber while observing the sphygmomanometer within the chamber and listening for the first audible flow signal from the Doppler detector, corresponding to the systolic blood pressure. To minimize the risk of fire in the oxygen-filled monoplace hyperbaric chamber, the patient, Doppler detector, and chamber were grounded. Doppler readings obtained from nine normal subjects whose arterial pressures were being measured with indwelling radial arterial catheters (approved as part of another study by the hospital's Investigational Review Board) compare closely with the subject's blood pressures measured with this noninvasive method: 114±7.6 mm Hg (mean±1 SD) compared to 112±8.1 mm Hg, respectively (n=92 measurements in 8 subjects). We conclude that this noninvasive method of monitoring blood pressure within the monoplace hyperbaric chamber is accurate and suitable for monoplace clinical purposes.This study was supported by a grant from the Deseret Foundation of the LDS Hospital, Salt Lake City, UT.We wish to thank the subjects who volunteered for this investigation, and we appreciate the help of Pam Evans, RRT, and the rest of the hyperbaric staff who assisted in the data collection.     

Pulse Oximetry Monitoring and Late Postoperative Hypoxemia on the General Care Floor

Hypoxemia has long been recognized as a risk to patients in the operating room and postanesthesia care unit, and hemoglobin oxygen saturation (HbO₂) monitoring with pulse oximetry has become a standard of care in these areas. There is growing evidence, however, suggesting that later postoperative hypoxemia also may play a role in organ dysfunction leading to morbidity and mortality. Economic pressures to move patients earlier from expensive postanethesia recovery and intensive care areas to the general care floor – where nurse-to-patient ratios are lower and lines of sight and sound may be impaired by walls and curtains – may lead to inadequate surveillance of at-risk patients. These patient-management trends underscore the importance of improved monitoring of respiratory status on the general care floor. In this environment, telemetric pulse oximetry monitoring may represent a cost-effective approach to maximizing quality of care while enhancing risk management. This review discusses late postoperative hypoxemia and identifies areas for further investigation.     

老年患者动脉弹性功能与围术期血压的相关性

目的：研究老年患者动脉弹性功能与围术期血压变化的关系。方法：随机选择68例ASA分级Ⅰ-Ⅱ级行全麻手术的老年患者,根据检查所得动脉弹性的结果分为四组,分别是A组（C1、C2均正常）,B组（C1异常,C2正常）,C组（C1正常,C2异常）,D组（C1、C2均异常）。测量其术前血压及全麻诱导8分钟后的血压水平。结果：动脉弹性功能不良的患者其术前MAP较高,且全麻诱导以后血压波动的比例较大。结论：高血压病的老年患者动脉弹性功能普遍降低;动脉弹性下降的老年病人全麻诱导后血压波动较大。     

Factors that Affect Pulse Wave Time Transmission in the Monitoring of Cardiovascular System

Objectives Vascular transit time (VTT) can be defined as the first heart sound of the phonocardiography (PCG) signal to its arrival at the photoplethysmography (PPG). Studies have shown that monitoring VTT can be useful as an early prognosis of cardiac diseases. However, there is limited study conducted to understand the physiologic factors that affect VTT at the upper limb. In this study, the effect associated with difference in subject height, weight, heart rate, mean arterial pressure, systolic and diastolic blood pressure was assessed. Methods A study population of 31 healthy Chinese young adults (21 male; age range 20–33 yr) were recruited. PCG and PPG were recorded non-invasively from the fourth costal cartilage at the midclavicular line and right index finger, respectively. A single sample Kolmogorov–Smirnov (K–S) goodness-of-fit hypothesis test, a univariate linear regression analysis, and a multiple linear regression modelling were performed on the VTT measurements and the associated physiologic parameters. Results The results from the K–S test showed that the physiologic parameters and VTT measurements had a normal cumulative distribution function. Furthermore, all physiologic parameters were significantly and independently related to VTT (P < 0.05). Based on these physiological parameters, a VTT regression model was also derived (r ² = 0.79). Conclusions The findings herein suggest that the observed physiologic parameters have significant contributions to the nominal VTT value of a subject. Unlike pulse transit time, the VTT technique has the added advantage that the left ventricular isometric contraction time is not included in the timing derivation. Foo JYA, Wilson SJ, Wang P. Factors that affect pulse wave time transmission in the monitoring of cardiovascular system.     

Effect of Skin Pigmentation on Pulse Oximetry Accuracy in the Emergency Department

Abstract. Objective:To determine whether pulse oximeter (PO) accuracy and signal quality are affected by level of skin pigmentation.
Methods:Observational study in a community hospital ED. Consecutive adult patients undergoing arterial blood gas determination were enrolled into the study. Skin pigmentation was determined by comparison with standardized color swatches under controlled lighting; assigned values were used to stratify patients into 3 groups (light, intermediate, and dark) using predetermined criteria. Simultaneous with arterial blood sampling, staff recorded PO reading of O₂ saturation using the Nellcor D-25 oximeter. PO values were compared with criterion standard values measured using a 4-wavelength spectrophotometer or cooximeter. PO signal quality also was recorded. Bias (the mean difference between PO and co-oximeter-measured values of hemoglobin saturation) and precision (the standard deviation of the bias) were calculated. Groups were compared using one-way ANOVA, Bart-lett's test for variances, and x² test.
Results:O₂ saturation data were obtained for 284 patients. Bias values did not differ between the 3 skin pigment groups (p = 0.79). Precision was of borderline significance (p = 0.05), but there was no dose-response relation between skin pigmentation and precision. Study personnel reported suboptimal PO function most often among patients in the dark group (p = 0.003), but this finding was of no clinical significance. PO signal failure was rare (<1% of all patients).
Conclusions:Although several prior studies suggest the contrary, this study found that skin pigmentation does not affect the bias or precision of pulse oximetry. Furthermore, skin pigmentation has no clinically significant effect on PO signal quality.     

危重病人无创伤动脉血压监测的相关因素研究

目的在危重病人中,研究影响心电监护仪测量血压的相关因素.方法共45例病人,根据上臂周长分成3组,分别进行心电监护仪测量、听诊器法卧式血压计测量血压.结果在二者比较中,其差值是(-3.54±2.84)mmHg(收缩压)、(-4.82±1.33)mmHg(舒张压);82.34%的差值小于10mmHg,而有17.67%的差值大于10mmHg.使用强心剂亦对测量血压产生影响,而且,不同的袖带(即1组与2、3组)之间均存在差异.结论在危重病人中,虽然心电监护仪测量血压存在偏差,但是绝大多数的测量数据在临床上是能够接受的.     

不同留置针在外周动脉血压监测中的安全性比较

目的比较直式留置针和带延长管留置针应用于外周动脉血压监测中的安全性。方法将2009年10月至2010年12月佛山市某三级甲等医院ICU行有创动脉血压监测的100例患者随机分为观察组和对照组各50例,观察组使用20 G带延长管留置针,对照组使用20 G直式静脉留置针。比较两组患者的置管意外(导管折叠、脱出和阻塞)发生率、穿刺点渗血情况和置管时间。结果观察组导管折叠和脱出的发生率、穿刺点渗血率低于对照组,而置管时间3 d以上者多于对照组,差异均有统计学意义(P<0.05)。结论有创动脉血压监测时使用带延长管的留置针,可减少导管折叠、脱出和穿刺点渗血的发生率,延长留置时间,在减轻患者痛苦和经济负担的同时,也减少了护理人员的工作量。     

原位肝移植围术期混合静脉血氧饱和度改变及临床意义

目的 观察原位肝移植围术期混合静脉血氧饱和度（SvO2）的变化及其临床意义。方法 20例终末期肝硬化患者接受原位肝移植术。采用心排仪持续监测围术期SvO2、氧供（DO2）、氧耗（VO2）、氧摄取率（ER02）、体温、心排血量（CO）、平均动脉压（MAP）的变化，分析肝移植围术期SvO2与上述各指标的相关性。结果 SvO2在无肝期前15min较术前增高（P〈O．05），在无肝期30min较无肝期前15min显著降低（P〈0．05），在新肝期30min和术毕较术前均显著增高（P均〈O．05）。机体DO2、VO2在无肝期30min均显著降低（P均〈O、05），而在进入新肝期后均显著增高（P均〈O、05）；ERO2进入新肝期后显著增加（P〈O.05）。SvO2在各时间点均与VO2有显著相关性（P均〈O．05），而与DO2、血红蛋白无相关性（P均〉0．05）；SvO2术前与CO有显著相关性（P〈O．05），其他时间点均无相关性（P均〉O．05）。结论 原位肝移植围术期持续监测SvO2对于改善氧代谢具有重要的临床意义。     

对原发性高血压患者采用自测血压干预的效果评价

目的评价自测血压对高血压患者的行为依从性、生活方式及血压的影响。方法 118名老年原发性高血压患者随机分为对照组和自测血压组。6个月后测量各组患者的血压,评价其行为依从性水平,了解其生活方式。结果与对照组相比,自测血压组患者行为依从性提高,舒张压[(74.85±14.19)vs(82.12±13.64)mmHg(1 mmHg=0.133 kPa)]、男性腰围[(78.03±6.68)vs(81.94±7.36)cm]、膳食盐[(7.56±2.34)vs(8.76±1.96)g/d]、油摄入量[(26.17±6.60)vs(29.85±6.12)g/d]、吸烟率(3.4%vs 15.5%)降低,积极参加运动的比例升高(P0.05);体质量指数、收缩压、女性腰围差异则没有统计学意义(P0.05)。结论高血压患者实施自测血压有助于提高治疗行为依从性,建立健康的生活方式,更好地控制舒张压。     

Self-reported Pain Scores in the Emergency Department: Lack of Association with Vital Signs

Background: Some practitioners and investigators have presumed relationships between pain scores and heart rate, blood pressure, or respiratory rate. Previous literature has not adequately addressed the association of pain and vital signs.
Objectives: To identify any association between self-reported pain and heart rate, blood pressure, or respiratory rate.
Methods: In this retrospective, observational study, emergency department patients older than 17 years of age presenting between May 2004 and April 2005 with verifiable painful diagnoses (including nephrolithiasis, myocardial infarction, small bowel obstruction, fracture, burn, crush injury, stab wound, amputation, corneal abrasion, and dislocation) were identified. Data were extracted from the hospital's database, including patients' age, gender, emergency department diagnosis, self-reported pain score, heart rate, blood pressure, and respiratory rate.
Results: Among 1,063 subjects, the most common diagnoses were nephrolithiasis (25%; n = 267) and fracture (23%; n = 249). The mean (± SD) triage pain score was 7 (± 3). The mean (± SD) heart rate was 85 (± 16) beats/min, mean (± SD) systolic blood pressure was 141 (± 23) mm Hg, and mean (± SD) respiratory rate was 19 (± 3) breaths/min. There were no clinically significant differences in mean vital signs across the individual pain scores, as demonstrated by overlapping confidence intervals across pain scores.
Conclusions: No clinically significant associations were identified between self-reported triage pain scores and heart rate, blood pressure, or respiratory rate.     

Evaluation of the radial artery applanation tonometry technology for continuous noninvasive blood pressure monitoring compared with central aortic blood pressure measurements in patients with multiple organ dysfunction syndrome

Purpose

We compared blood pressure (BP) measurements obtained using radial artery applanation tonometry with invasive BP measurements using a catheter placed in the abdominal aorta through the femoral artery in patients with multiple organ dysfunction syndrome (MODS).

Materials and Methods

In 23 intensive care unit patients with MODS, we simultaneously assessed BP values for 15 minutes per patient using radial artery applanation tonometry (T-Line TL-200pro device; Tensys Medical Inc, San Diego, Calif) and the arterial catheter (standard-criterion technique). A total of 2879 averaged 10-beat epochs were compared using Bland-Altman plots.

Results

The mean difference ± SD (with corresponding 95% limits of agreement) between radial artery applanation tonometry–derived BP and invasively assessed BP was + 1.0 ± 5.5 mm Hg (− 9.9 to + 11.8 mm Hg) for mean arterial pressure, − 3.3 ± 11.2 mm Hg (− 25.3 to + 18.6 mm Hg) for systolic arterial pressure, and + 4.9 ± 7.0 mm Hg (− 8.8 to + 18.6 mm Hg) for diastolic arterial pressure, respectively.

Conclusions

In intensive care unit patients with MODS, mean arterial pressure and diastolic arterial pressure can be determined accurately and precisely using radial artery applanation tonometry compared with central aortic values obtained using a catheter placed in the abdominal aorta through the femoral artery. Although systolic arterial pressure could also be derived accurately, wider 95% limits of agreement suggest lower precision for determination of systolic arterial pressure.     

Influence of Pulse Oximetry and Capnography on Time to Diagnosis of Critical Incidents in Anesthesia: A Pilot Study Using a Full-Scale Patient Simulator

Objective. Many studies (outcome, epidemiological) have tested the hypothesis that pulse oximetry and capnography affect the outcome of anesthetic care. Uncontrollable variables in clinical studies make it difficult to generate statistically conclusive data. In the present study, we eliminated the variability among patients and operative procedures by using a full-scale patient simulator. We tested the hypothesis that pulse oximetry and capnography shorten the time to diagnosis of critical incidents. Methods. A simulator was programmed to represent a patient undergoing medullary nailing of a fractured femur under general anesthesia and suffering either malignant hyperthermia, a pneumothorax, a pulmonary embolism or an anoxic oxygen supply. One hundred thirteen anesthesiologists were randomly assigned to one of two groups of equal size, one with access to pulse oximetry and capnography data and the other without. Each anesthesiologist was further randomized to one of the four critical incidents. Each anesthetic procedure was videotaped. The time to correct diagnosis was measured and analyzed. Results. Based on analysis of 91 of the subjects, time to diagnosis was significantly shorter (median of 432 s vs. >480 s) for the anoxic oxygen supply scenario (p = 0.019) with pulse oximetry and capnography than without. No statistical difference in time to diagnosis was obtained between groups for the other three critical incidents. Conclusions. Simulation may offer new approaches to the study of monitoring technology. However, the limitations of current simulators and the resources required to perform simulator-based research are impediments to wide-spread use of this tool.